


nocturne

by ictus



Category: The Umbrella Academy (TV)
Genre: Angst and Porn, Implied/Referenced Drug Use, M/M, Pre-Canon, Sharing a Bed, Sibling Incest
Language: English
Status: Completed
Published: 2019-11-09
Updated: 2019-11-09
Packaged: 2021-01-26 03:16:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,719
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21367288
Author URL: https://archiveofourown.org/users/ictus/pseuds/ictus
Summary: The thing about Klaus is that he’s ruthlessly,impressivelytenacious. When Diego thinks of boneheaded stubbornness, he thinks of Luther first and foremost; but there’s something to be said for Klaus’s ability to latch on to an idea. Provided it’s in his best interests, Klaus will follow through on any plan until the bitter end, wearing down anyone who stands in his path by sheer irritation rather than any sort of manipulative skill. Diego already knows how this is going to end. He figures they might as well skip ahead to the part where he gives in.When Klaus shows up looking for a place to crash, Diego knows he's in for a long night.
Relationships: Diego Hargreeves/Klaus Hargreeves
Comments: 18
Kudos: 198
Collections: Shipoween 2019 - The Halloween Ship Exchange!, The umbrella academy





	nocturne

**Author's Note:**

  * For [shadowsapiens](https://archiveofourown.org/users/shadowsapiens/gifts).

> I'm sorry this is so late! Happy _looks at smudged writing on hand_ Shipo... woon? I hope you had a good one ♥ 
> 
> Many thanks to lileura for the beta!

There’s someone knocking on Diego’s door.

Diego closes his eyes and entertains an elaborate fantasy about all the ways he’s going to inflict harm on this person. He waits them out for five whole minutes until he accepts they’re unlikely to be deterred, then he gets out of bed and trudges towards the door. Whoever it is had better be either dead or dying, because there’s little else that could justify showing up unannounced at three in the morning. On his way, he grabs a knife and tucks it up his sleeve. Just in case.

Diego unlocks the deadbolts and undoes the chain, and when he opens the door he’s hit by the feeling that this is going to be a long night. The man on his doorstep has his back turned, but Diego would recognise him anywhere.

“How the hell did you find out where I live?”

Klaus turns, his face breaking out into a grin. He looks surprised to see Diego, as if he’d forgotten where he was and why he was there in the five minutes it took Diego to answer the door. Knowing Klaus, it’s probably not far off.

“Oh hey,” Klaus says with a jaunty wave.

“How did you find out where I live?” Diego repeats through gritted teeth. Klaus seems reluctant to answer, but Diego has his suspicions; Vanya always was a soft touch when it came to Klaus, and Diego’s been stationary for long enough that she probably still has his address.

“It’s good to see you! It’s been what, two years?” Klaus spreads his arms for a hug, but Diego’s quick to stop him with a hand on his chest.

“I’m not giving you any money.”

Klaus’s eyes widen, a look of mock hurt passing his face. “Money, who said anything about money? I just wanted to see my brother! Can I come in?”

“No,” Diego says, but Klaus is already pushing past him, squeezing between Diego and the doorframe.

“Oh this—this is _nice_,” Klaus says as he takes in the renovated boiler room. His eyes linger on the exposed pipes and the bare concrete floor. “Real nice,” he adds, shrugging off his coat while Diego locks the door behind him. The saddest part is that Klaus doesn’t even sound like he’s joking.

“It’s cheap,” Diego says defensively. “Who let you in?”

“Some old guy with a face like a ballsack. Said he owned the place and you just mop the floors for him.”

Diego bristles, but Klaus isn’t paying attention to him. He’s begun rifling through Diego’s kitchen, opening and closing all the cabinets, looking for something in particular. When he reaches for the liquor cabinet, Diego doesn’t hesitate: he drops the knife into his palm and launches it at Klaus. The knife misses Klaus’s hand by half an inch and hits the cupboard door instead, embedding itself in the wood with a satisfying _thud._

Klaus shrieks and hastily withdraws his hand.

“Alright, alright, geez,” he says, holding up his hands in surrender. “Can’t blame a guy for trying.”

Diego marches towards him and wrenches the knife out of the warped wood of the cupboard. Knife in hand, he grabs Klaus by the chin so he’s forced to meet Diego’s eyes.

“Klaus, what are you doing here?”

“Well,” Klaus says, his eyes casting to the side, “it’s been getting pretty cold out and I’m sort of—sort of between places at the moment.”

“You mean to say that you’re homeless.”

Klaus shrugs. “Po-tae-to, po-tah-to. Anyway,” he says, slinging an arm around Diego’s shoulders, “seeing as though we’re family—”

“We are not family,” Diego grits out, pushing Klaus off him.

“Okay, let me try again: seeing as though we were both subject to a shared childhood where a heartless monster experimented on us like zoo animals—”

Diego huffs out a laugh in spite of himself.

“—I thought that maybe perhaps I could ask a favour of you.”

The thing about Klaus is that he’s ruthlessly, _impressively_ tenacious. When Diego thinks of boneheaded stubbornness, he thinks of Luther first and foremost; but there’s something to be said for Klaus’s ability to latch on to an idea. Provided it’s in his best interests, Klaus will follow through on any plan until the bitter end, wearing down anyone who stands in his path by sheer irritation rather than any sort of manipulative skill. Diego already knows how this is going to end. He figures they might as well skip ahead to the part where he gives in.

“What do you need, Klaus?”

Klaus’s grin is blinding. “I was wondering if I could crash here for the night?”

Diego rolls his eyes. “Klaus—”

“Just for one night! I’ll be so quiet, you won’t even know I’m here.”

_“Klaus.”_

“Diego, please. It’s freezing out, and they say it’s going to start snowing tonight. Please?”

Diego runs his tongue over his teeth. Klaus looks so pathetic, his eyes wide and desperate, and Diego can’t say no even though he _knows_ he’ll regret this.

Hating himself, Diego relents. “One night,” he says, pointing at Klaus with the tip of his blade to punctuate his point.

Klaus clasps his hands together. “Thank you so much, you’re the best! I promise you won’t even know I’m here.”

“Don’t make promises you can’t keep.”

Before Klaus can say anything else, Diego pulls away. He rifles through his closet for a sleeping bag and drops it on the sofa without ceremony.

“Alright, here are the rules: couch,” Diego says, gesturing to the sofa with his knife. “Shower,” he adds, pointing in the general direction of the bathroom. “This is the bed. And this is the couch. I sleep here, you sleep there.”

“Okay, but what about—”

“Other rules: you do not touch my liquor, and you do not smoke inside. And if you steal from me, if you take so much as a _dime_ from this place”—Diego steps into Klaus’s space and presses the tip of his blade under his chin—“I’ll cut off your balls and shove them down your throat.”

Klaus’s eyes flicker down to the blade, then back up to Diego’s face. “Got it.”

*

Surprisingly, Klaus keeps his end of the bargain—at least at first.

Diego’s exhausted from a long night of patrol, dealing with the scumbags that the cops let slip through their fingers. He’s bruised, beaten, and frankly, too tired for this shit. Diego waits until Klaus disappears into the bathroom before he collapses face-first onto the bed, falling asleep to the sound of the shower running.

He wakes sometime later to the covers being drawn off him.

“Klaus,” he says into his pillow, unwilling to move.

For once, Klaus doesn’t say anything, just slips into bed behind him. He presses his face in between Diego’s shoulder blades and tangles their legs together, his feet icy cold against Diego’s heated skin.

“Klaus,” Diego says, a little louder this time. “Remember the rules?”

“’M cold,” Klaus murmurs against his back.

“There are extra blankets in the closet.” Diego’s limbs are heavy with fatigue, and he can do little to detangle himself from Klaus. Klaus seems to take his lack of resistance as permission, snaking an arm around Diego’s waist in a way that Diego refuses to think of as spooning.

“D’you remember when we were kids and we used to do this?”

A sickening feeling curdles in Diego’s gut, some unholy combination of desire and shame.

“No.”

Klaus puffs out a laugh, his breath hot on the nape of Diego’s neck. “Come on, you remember.” Klaus’s hand has slipped lower so it rests on Diego’s hip, a simple touch that would seem innocent if it were coming from anyone else. “You know, I never told anybody about that. Not a soul.”

Diego sucks in a breath. His heart’s racing so fast, he’s almost sure Klaus can feel it. He suddenly feels very awake.

“I didn’t either,” he says a little too quickly.

Klaus snorts. “Yeah. But I didn’t make you promise not to.”

The pang of guilt gets Diego right in the chest, splintering into tiny pieces that lodge in his lungs and make it hard to breathe. His hand itches with the desire to push Klaus away, to kick him out of his bed, out of his _life_. Diego’s always had a hair-trigger temper, and anger is easier to stomach than guilt. It’s so easy to give into that, to let that familiar irritation get the better of him.

“What we did—we were just kids. I was too stupid to know any better.”

Diego’s tone is cold, dismissive in the worst way, but Klaus doesn’t flinch and he doesn’t pull away. He just slips his hand under Diego’s T-shirt, his fingers splaying over the flat of his stomach. The feeling of Klaus’s body against his is familiar in all the ways that Diego doesn’t want to admit. Sure, they’re adults now, but all those sensations—Klaus’s breath hot on his neck, his hips slowly rocking against Diego—they’re all the same.

Klaus says Diego’s name and it sounds like a plea, desperate in a way that’s impossible to ignore. Diego knows he should push Klaus away, should send him back to the couch and pretend this never happened. But then Klaus says his name again and it brings all those long-buried memories to the surface—

_(Klaus joining him in the shower, scrubbing caked blood out of his hair; Klaus comforting him after he gets his tattoo, pressing a soft kiss to the inside of his wrist; Klaus finding him after Ben’s wake, holding out a bottle of stolen whiskey like a peace offering)_

—and Diego can’t find it in himself to say no.

For someone as persistent as Klaus, Diego’s silence is the only invitation he needs. Diego knows he outmatches Klaus physically, has done so since they were sixteen, yet somehow he’s helpless to resist Klaus pulling him onto his back. The bed dips as Klaus props himself up on his elbow, then he tilts Diego’s face towards him with the softest of touches.

Diego anticipates the kiss, but it’s somehow still a surprise when Klaus presses their lips together. It’s exactly as Diego remembers it: this secret, unspeakable thing between them, kept only for stolen moments or beneath the cover of darkness. Diego pauses a beat, waits until Klaus relaxes against him before he takes control, deepening the kiss and steadying Klaus with a hand on his jaw. Klaus moans a little at that, the sound achingly familiar, and Diego wants to hear _more_. He easily reverses their positions, shifting until Klaus is laid out beneath him, and when their hips align Diego can feel that Klaus is hard and wanting.

“God,” Klaus says as he presses his hips against Diego’s. Klaus is panting open-mouthed, and it’s the kind of invitation that Diego can’t resist. He presses his mouth to Klaus’s lower lip and takes it between his teeth, not drawing back until Klaus is whimpering. Klaus is already rutting against his thigh, tiny movements of his hips that have him gasping and sighing.

“Hold on,” Klaus says, reaching for the light.

“Don’t.”

Diego can sense Klaus still in the darkness, and for once in his life, Klaus obeys. Diego can’t explain why he needs to keep the lights off, can’t explain that the second he sees Klaus splayed in front of him is the second that this becomes suddenly real: undeniable and inexcusable.

So instead he gets his hands under Klaus’s T-shirt and runs his fingertips over his chest until Klaus is shifting beneath him and tugging his shirt off the rest of the way. Touching Klaus is like muscle memory, his hands tracing the lines of Klaus’s body as if he’s acting on some deeper instinct. Diego had first learned Klaus’s body in darkness until every dip and curve was etched into his fingertips. And now he relearns Klaus’s body in the same way; in the dark and working off touch alone, his fingers gliding over the planes of his chest, the jut of his ribs.

Diego runs his hands down Klaus’s body until they reach the hollow of his hipbones, then he draws his hands lower still. Klaus swears when Diego runs a hand over his erection, his hips rising off the bed as he arches into Diego’s touch. Diego knows that if he stops for even a second, he’ll be hit with every reason why this is a terrible idea. So he doesn’t stop, doesn’t pause, just hooks his fingers into the waistband of Klaus’s underwear and tugs it down. Diego can’t make out much through the darkness, but he doesn’t need to; he knows that Klaus’s dick is hard and leaking where it curves towards his stomach, knows that Klaus is flushed all the way down to his chest. When Diego draws away, Klaus’s hands convulse at his sides, his hips still twitching as if he’s trying to fuck thin air.

“Diego.” Klaus’s voice is whisper-soft, as if they’re still sixteen and need to keep quiet. 

“You should hear yourself. You’re so desperate for it, aren’t you?” Diego means it as a slight, just another barb in this decade-long feud of theirs, but Klaus only moans and cants his hips, the word _yes_ passing his lips on a sigh.

Diego kneels between Klaus’s spread legs and runs his hands over the inside of his thighs, enjoying the feeling of drawing this out. By the time Diego finally makes it to his cock, Klaus is a writhing mess, letting out a constant stream of gasps and pleas. Klaus is already sticky with precome, and when Diego presses his thumb to the slit, the sound he makes is utterly debauched.

“Diego, please,” Klaus gasps, and that’s all it takes before Diego’s ducking down and wrapping his lips around Klaus’s cock. When Diego swallows him down halfway, Klaus moans like it’s the best feeling ever. It’s not long before he’s edging himself deeper, tiny movements of his hips that speak volumes of his desperation, and Diego has to get a grip on Klaus’s hips in order to hold him steady. Diego draws back to suck on the head and run his tongue along the underside, caught up in the nostalgia from the countless other times they’ve done this. Diego quickly finds a rhythm, and when he manages to take Klaus all the way down, Klaus actually shouts, his hands buried in Diego’s hair as he comes down Diego’s throat.

Diego’s spluttering by the time he pulls off, tears stinging the corners of his eyes.

“Jesus Christ, warn a guy.” Diego wipes his mouth on the back of his hand, and when he licks his lips he tastes Klaus.

“Mmm, sorry,” Klaus says, not sounding sorry at all. He’s breathing hard, his chest rising and falling with every gasp. Diego can’t see him but can imagine what he must look like: lips parted, face flushed, already lost to the post-orgasm haze. Diego’s about to make a comment about reciprocation when Klaus says—

“You can fuck me if you want.”

All the air seems to leave Diego’s chest at once. This is uncharted territory for them. They never got this far, not back when they were teenagers, and certainly not anytime since. Klaus had offered once, and Diego had stormed out of his own bedroom, refusing to touch him for a whole week. Diego had worked so hard to convince himself that this didn’t mean anything, that every time would be the last. He’d drawn a line in the sand, one he refused to cross, and to go back on it now feels like admitting something he’s not willing to accept.

“I’m serious,” Klaus says, oblivious to Diego’s existential crisis. He shifts onto his stomach and cants his hips backwards, a clear invitation, and for one brief moment Diego allows himself to picture it: sinking into Klaus, inch by inch. Feeling Klaus hot and tight around him. The sounds he would make when Diego angles his hips just right.

“Fuck.” Diego squeezes himself through his underwear. He can feel a damp patch growing at the tip, desperately hard at the thought of actually being inside Klaus. But there’s something holding him back.

“C’mon,” Klaus says, and actually spreads his legs. Diego bites back a groan at the thought of Klaus spread out beneath him, begging with his entire body. There’s shifting in the darkness, the sound of a drawer opening as Klaus rifles around for something. Klaus swears to himself until he finally finds what he’s looking for, then presses a bottle into Diego’s hands.

“Here,” Klaus says.

Diego takes the bottle wordlessly. He’s afraid to break the tense silence that’s fallen over the room, the one that Klaus isn’t even aware of. Diego pulls his shirt over his head and shucks off his underwear while Klaus shifts restlessly.

“Hurry up before I die of boredom.”

There’s a quip on the tip of Diego’s tongue, something along the lines of _you’ll take what I’ll give you when I’m good and ready_, but Diego can hardly form the words. He uncaps the lube and slicks himself up. But when he settles between Klaus’s spread legs and presses his body along Klaus’s back, he takes a moment to press Klaus’s thighs together.

“What are you—_oh_.” Klaus cuts himself off with a gasp as he feels Diego’s cock slide between his thighs, gliding over the cleft of his ass. Diego repeats the movement as he draws his hips back, the press of Klaus’s thighs feeling impossibly good. Klaus is so responsive to his every touch, arching his back to meet Diego’s hips, as if he really were getting fucked.

It should feel degenerate. It shouldn’t feel this good. Rutting against each other like a couple of horny teenagers—and hell, even when they were teenagers, they never did _this._ There’s no finesse and there’s no technique, just Diego’s desperate desire to drive his body into Klaus’s as he chases his own release.

It’s not until Klaus starts panting Diego’s name that Diego feels his own voice coming unstuck.

“You like that?” Diego murmurs into his ear, nipping at his earlobe. Klaus nods frantically, arching against him so their bodies are pressed together. Klaus gasps every time Diego rocks into him, and Diego revels in the feeling of Klaus beneath him, that skin-on-skin contact setting his nerves alight. As the pleasure builds, each one of Klaus’s gasps and moans fades to white noise until Diego’s frantic pulse is all he can hear and he’s spilling messily between Klaus’s legs. It’s filthy and it’s obscene, but Diego can’t help but fuck through his own mess as he rides out the aftershocks. Klaus’s thighs are slick and gripping him tight, urging Diego on even as he starts to shudder with hypersensitivity.

As the pleasure fades, Diego summons the last of his energy to push himself off Klaus. Already he feels uncomfortably sticky, and he knows that Klaus is probably feeling much the same.

“Klaus.” Diego shakes his shoulder. “Klaus.”

Klaus makes a noise into the pillow, something unintelligible that sounds a lot like _ughn_.

“Klaus, get your ass up. I don’t want you getting spunk on my sheets.”

“Well maybe you should have thought of that before you—”

“_Now_,” Diego says, but this time there’s no response. “Unbelievable,” he mutters under his breath, heaving himself out of bed. He grabs a washcloth from the bathroom and cleans himself, then returns to the bed where Klaus is still splayed face-down. Diego hesitates for a moment before drawing the cloth between Klaus’s legs. It feels almost too intimate to be touching Klaus like this. There’s no sexual intent to his touch, and his hands are uncharacteristically gentle as he wipes Klaus down.

“Klaus,” he says once he’s tossed the cloth into the hamper. “Klaus, move over.”

Klaus doesn’t respond. He’s completely motionless. Diego’s gripped by a familiar panic, the kind that claws its way up through his chest and strangles his lungs. He says Klaus’s name again, and this time he stutters, hitting the _k_ sound twice. He pushes Klaus onto his back and taps his cheek a couple of times.

“Klaus,” he says again and this time, Klaus shifts under his hands.

“Yeah?” Klaus mumbles.

Diego breathes out a sigh. His relief is quickly replaced with a surge of anger, and when Klaus reaches for him, Diego slaps his hand away.

“What did you take?”

Klaus pulls away from him. “Nothing.”

“Klaus.” Diego reaches to turn on the bedside lamp and sure enough, Klaus’s pupils are blown huge, his lip swollen from where he’s been chewing on it. “Did you bring drugs into my house?”

Klaus sighs. “Just leave it, okay?”

Diego grits his teeth. He should have known that Klaus was high, should have thought to check his pockets before even letting him in. Diego knows that one day, Klaus is going to end up behind bars or in a body bag, and Diego’s going to think of every time that he could have intervened, all the moments that he turned a blind eye, and he’ll know that he’s to blame.

But now Klaus is tugging him close, pulling him down onto the mattress so they’re pressed together side by side. Some of Diego’s anger dissipates as Klaus drapes an arm over him, holding him close in a way that Diego’s never allowed before. Diego had always kicked Klaus out straight after sex, had insisted that they would get caught if he stayed in Diego’s room. And Klaus—Klaus had always nodded like he’d understood. Now Diego realises Klaus must have understood better than he’d guessed.

“Tomorrow, when we wake up”—Klaus shifts so he’s looking Diego in the eye—“are you going to pretend this never happened?”

Diego pauses a beat. His mind is frantic with all of the things he could say to that, every excuse and denial more feeble than the last.

But his hesitation must be an answer in itself because Klaus lets out a little _huh_, just the faintest puff of air on Diego’s lips, so quiet Diego would have missed it if he hadn’t felt it. Then he wordlessly reaches for the bedside lamp, and plunges the room into darkness.

**Author's Note:**

> You can also find me on [twitter](https://twitter.com/scansionictus).


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